Water-curable compositions, based on thermoplastic polymers having hydrolyzable silane moieties are becoming increasingly attractive, on a commercial scale, as it is possible to extrude such compositions, as for example, about wires and cables under a wide variety of processing conditions not possible with compositions containing organic peroxides. Furthermore, coverings on wires and cables extruded from water-curable compositions can be cured or crosslinked by a simple operation wherein the covered wire is passed through a heated water-bath.
One disadvantage of water-curable compositions, however, is the water sensitivity of these compositions. Compositions containing water-curable thermoplastic polymers having hydrolyzable silane moieties tend to crosslink under normal conditions of handling and storage. As a result, the relatively poor shelf life of such compositions has tended to limit the wide commercial acceptance of such compositions, particularly in the United States.
Modification of water-curable compositions, in order to alleviate the problem of premature crosslinking, is described in my U.S. Pat. No. 4,526,930, patented July 2, 1985. According to U.S. Pat. No. 4,526,930, compositions are formulated, containing relatively water-stable thermoplastic polymers having hydrolyzable silane moieties, which are only activated or made readily water-curable by the reaction therewith of an organo titanate having at least one readily hydrolyzable group, which ester exchanges with an ester group of the silane.